Catholicism is an instinctively fleshy religion — just ask the many pilgrims who spontaneously traveled to see the (possibly incorrupt) body of Sister Wilhelmina Lancaster in the past couple of weeks. This fleshiness is appealing to human beings because human beings are creatures of flesh and blood. It is not as if the Church, in choosing to allow the veneration of corpses and relics, is creating some strange superstition out of whole cloth; rather, the church is allowing people to approach religion in one of the ways that is most natural and instinctive to us: through our bodies.

This human instinct to approach religion corporeally is not one of those aspects of fallen or distorted humanity that needs to be left behind. Nor is it a premodern, preindustrial tendency from which better education and a well-developed 21st-century intelligence should be able to graduate. We Catholics have the best possible imprimatur for our fleshy approach to religion: the words of Jesus himself. It was Jesus, after all, who said to the confusion of the listeners:

I am the living bread which came down from heaven. If any man eat of this bread, he shall live forever; and the bread that I will give, is my flesh, for the life of the world. … Amen, amen I say unto you: Except you eat the flesh of the Son of man, and drink his blood, you shall not have life in you. He that eats my flesh, and drinks my blood, hath everlasting life: and I will raise him up in the last day (John 6:51-2 and 54-5).

Grappling with that text is, to be sure, not only a problem for Jesus’ contemporaries: one finds, among the medievals, along with a strong belief in the Real Presence, a lively debate about how to characterize this mystery in philosophical terms — how to explain it so that, although the mystery can never be fully comprehended, objections may be answered and apparent contradictions erased.

This debate was renewed during the Protestant Reformation, when Luther and other reformers, having abandoned a Scholastic approach to reasoning through texts of Scripture, denied the Thomistic account of transubstantiation and suggested various other ways of understanding John 6, such as the consubstantiation held by some Lutherans and Anglicans today.

The scandal of Jesus’ words is, therefore, still very much with us. But for those who believe that they mean what the Church teaches (unofficially among the early Fathers of the Church, from Ignatius of Antioch in the first century through Augustine in the fourth, and dogmatically since the Fourth Lateran Council in 1215, a dogma that was affirmed by the Council of Trent), the idea that Jesus is truly present in the Holy Eucharist — Body, Blood, Soul and Divinity — is one of those things that keeps us coming back to church, even when disillusioned with priests and prelates.

We feel it — even irreligious people sometimes feel it — on entering a church. We whisper it to our children, especially at the consecration: Jesus is here.

Indeed, he is here; but that word “here,” as it happens, is a sticky one. St. Thomas Aquinas grapples with, among other Eucharistic topics, the issue of “the way in which Christ is in this sacrament” (Summa Theologiae, III, 76). He tackles the problem of the Real Presence through a distinctly neo-Aristotelian lens, invoking ideas like species, quality, substance and accident, and addresses specifically the question of whether Christ's body is present in the Blessed Sacrament as if it were in a place. (To which, instinctively, many Catholics would reply Yes; but Aquinas’ answer is, in fact, No.)

Aquinas is aware of the sort of objections that would be raised by reformers centuries later. He agrees, for example, that we cannot allow any definition of the sacrament that would imply that Christ's body “would be only on the particular altar where this sacrament is performed,” inasmuch as that body “is in heaven under its own species” (Reply to Objection 1).

In other words, when it comes to the Eucharist, Jesus is here; but that does not mean that we can somehow add up every consecrated host to make his body. The Eucharistic place where Christ’s body is, is instead “filled with the sacramental species” (Reply to Objection 2). That is, speaking roughly and nontechnically, the place where the Eucharist resides is filled with whatever is needed to inform the senses and intellect that this is bread and wine. (Colloquially, we speak of “the appearances of bread and wine,” but Aquinas would instead have used the language of species and accidents, words that had precise technical meanings within his philosophical school.) Indeed, when it comes to the Eucharist, Jesus is here, “but that word doesn’t mean what you think it means.”

But if Jesus is here, in the Eucharist, substantially albeit not in the way he is in a place, then in what place (if any) can Jesus be said to be? The obvious answer, in this case, is the correct one: his body as it rose, glorified and bearing the scars of his victory, is in heaven (see also III.54.4, Reply to Objection 3). If we say then that Jesus is here on the altar, meaning he is substantially present, we are right; but given that “here” usually implies what Shakespeare calls “a local habitation,” it might be nearer the truth to say, “That is Jesus.”

What happens at the consecration, then, is less a descent by the Godhead onto the altar, as if Jesus were to leave heaven to visit us (although pious imagery of this sort is barely less pious for its inaccuracy) but rather that, in the language traditionally applied by Catholics to the Eucharistic sacrifice, the curtain between heaven and earth is rent. Like the veil of the Temple at Christ’s death, the veil separating this world from the world to come is torn. As St. Paul puts it, there is a new “veil,” namely, “[Christ’s] flesh,” that provides us rather “a new and living way” of “entering into the holies” (see Hebrews 10:19-20). Almost truer to say (if we must use the language of place) that the Mass is not God coming down to earth but us being raised up to heaven. And more accurate than either localist formulation to say that, in the Blessed Sacrament, we taste and touch what is truly in heaven.

As Aquinas puts it in the poetry he wrote for this feast of Corpus Christi, Jesus the one who “expands the door of heaven”:

O salutaris Hostia,
Quae caeli pandis ostium.